Golf Club Head Alloy and Method of Using the Same to Produce a Golf Club Head

ABSTRACT

A golf club head alloy includes by weight percent 6.5-7.5% of aluminum, 1.0-2.5% of iron, 0.05-0.2% of silicon, less than 0.15% of oxygen, less than 0.1% of carbon, less than 0.05% of nitrogen, the rest being titanium and inevitable impurities. Furthermore, the golf club head alloy has a density of 4.35-4.39 g/cm3. A method of producing a light golf club head includes: providing a sheet blank produced from the above aluminum club head alloy; annealing the sheet blank at 500-800° C. for 30-90 minutes and forming a striking plate; coupling the striking plate to a club head body to form a club head semi-product; and performing aging heat treatment on the club head semi-product at 400-700° C. for 30-240 minutes.

CROSS REFERENCE TO RELATED APPLICATION

The application claims the benefit of China application serial No. 201710555705.3, filed on Jul. 10, 2017, and the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an alloy and, more particularly, to a golf club head alloy. The present invention also relates to a method of using the golf club head alloy to produce a golf club head.

2. Description of the Related Art

Manufacturers generally use titanium alloys to produce golf club heads for fulfilling the user's need of a light golf club head. As an example, a conventional golf club head alloy (64-Ti) includes by weight percent 6% of aluminum, 4% of vanadium, the rest being titanium and inevitable impurities. The density of this conventional golf club head alloy is about 4.41 g/cm³, and the weight of the striking plate of the resultant golf club head is about 41.10 g. Improvement to the weight is still possible. Thus, a need exists for a novel golf club head alloy and a novel method of using the novel golf club head alloy to produce a golf club head for the purposes of solving the above problem.

SUMMARY OF THE INVENTION

To solve the above problem, the present invention provides a golf club head alloy that can be used to produce a light golf club head.

The present invention further provides a method of using the above golf club head alloy to produce a light golf club head.

A golf club head alloy according to the present invention includes by weight percent 6.5-7.5% of aluminum, 1.0-2.5% of iron, 0.05-0.2% of silicon, less than 0.15% of oxygen, less than 0.1% of carbon, less than 0.05% of nitrogen, the rest being titanium and inevitable impurities. Furthermore, the golf club head alloy has a density of 4.35-4.39 g/cm³. Preferably, the golf club head alloy includes by weight percent 6.8-7.5% of aluminum, 1.55-1.95% of iron, 0.11-0.15% of silicon. Thus, the golf club head alloy according to the present invention has a lower density due to the composition ratio thereof and, thus, can be used to produce a light golf club head, which is the effect of the present invention.

In an example, the golf club head alloy has an aluminum equivalent of 7.5-9.2. Thus, the rolling rate of the golf club head alloy is enhanced, and the sheet formation rate in the subsequent procedures is increased.

A method of using the above golf club head alloy to produce a light golf club head according to the present invention includes: providing a sheet blank produced from the above aluminum club head alloy; annealing the sheet blank at 500-800° C. for 30-90 minutes and forming a striking plate; coupling the striking plate to a club head body to form a club head semi-product; and performing aging heat treatment on the club head semi-product at 400-700° C. for 30-240 minutes. Through use of the golf club head alloy, under the premise of maintaining a proper cannon shot durability of the resultant golf club head, the weight of the resultant golf club head is reduced. Furthermore, by performing the aging heat treatment on the club head semi-product, the cannon shot durability is further enhanced while reducing the bending deformations of the striking face in the horizontal direction (bulge) and the vertical direction (roll) after the cannon shot test, which are the effects of the present invention.

In an example, the striking plate has a tensile strength higher than 170 ksi, a yield strength higher than 150 ksi, an elongation of more than 10%, and a hardness of HRC 33-39.

In an example, the sheet blank is annealed at 650-800° C. for 40-50 minutes, and the aging heat treatment is performed on the club head semi-product at 550-650° C. for 30-120 minutes.

The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawing.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE shows a method of producing a light golf club head of an embodiment according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A golf club head alloy according to the present invention includes by weight percent 6.5-7.5% of aluminum, 1.0-2.5% of iron, 0.05-0.2% of silicon, less than 0.15% of oxygen, less than 0.1% of carbon, less than 0.05% of nitrogen, the rest being titanium and inevitable impurities. Preferably, the golf club head alloy includes by weight percent 6.8-7.5% of aluminum, 1.55-1.95% of iron, 0.11-0.15% of silicon. The golf club head alloy has a density of 4.35-4.39 g/cm³. Thus, the golf club head alloy according to the present invention can have a lower density by adjusting the composition ratio thereof.

Furthermore, the aluminum equivalent [Al]_(eq) of the golf club head alloy fulfills the equation of [Al]_(eq)=[Al]+10[O+C+2N] and is preferably 7.5-9.2. This not only maintains the lower density of the golf club head alloy but enhances the rolling rate of the golf club head alloy and increases the sheet formation rate in the subsequent procedures.

Thus, a manufacturer can use the above golf club head alloy to produce a light golf club head. Specifically, a method of producing a golf club head according to the present invention includes a sheet blank formation step S1, an annealing step S2, a club head semi-product formation step S3, and an aging heat treatment step S4, as shown in the FIGURE.

In the sheet blank formation step S1, the sheet blank is produced from the above golf club head alloy. For example, the manufacturer can press the golf club head alloy into an electrode ingot, which is then smeltered into a titanium alloy rod. Then, the titanium alloy rod is forged into a plate blank that is finally hot rolled into the sheet blank.

In the annealing step S2, the sheet blank is annealed at 500-800° C. for 30-90 minutes and forms a striking plate. Preferably, the sheet blank is annealed at 650-800° C. for 40-50 minutes. Through the temperature adjustment in the annealing step S2, the residual stress of the processing procedures can be effectively eliminated while softening the material. It is worthy to note that the annealing temperature should not exceed 800° C. during the annealing step S2 in order to avoid excessive softening that would lead to excessively large crystalline grains, thereby avoiding reduction in the tensile strength of the sheet blank. In this embodiment, the striking plate has a tensile strength higher than 170 ksi, a yield strength higher than 150 ksi, an elongation of more than 10%, and a hardness of HRC 33-39.

In the club head semi-product formation step S3, the manufacturer couples the striking plate to a club head body to form a club head semi-product. For example, the striking plate can be coupled to the club head body by welding, which can be appreciated by one having ordinary skill in the art. Redundant description is therefore not required.

In the aging heat treatment step S4, the aging heat treatment is performed on the club head semi-product at 400-700° C. for 30-240 minutes. Preferably, the aging heat treatment is performed on the club head semi-product at 550-650° C. for 30-120 minutes. The golf club head can be obtained accordingly.

The following tests are conducted to prove that a light golf club head can be produced from the golf club head alloy by the sheet blank formation step S1, the annealing step S2, the club head semi-product formation step S3, and the aging heat treatment step S4.

(A) Mechanical Properties of Striking Plates

In this test, after the sheet blank is formed from the golf club head alloy (including by weight percent 6.5-7.5% of aluminum, 1.0-2.5% of iron, 0.05-0.2% of silicon, less than 0.15% of oxygen, less than 0.1% of carbon, less than 0.05% of nitrogen, the rest being titanium and inevitable impurities), striking plates (group A1) are obtained by annealing at 780° C. for 45 minutes and are tested for measuring mechanical properties. As a comparative example, striking plates (group A0) are produced from the conventional golf club alloy (64-Ti) by the same procedures. The results are shown in Table 1.

TABLE 1 mechanical properties of striking plates of each group in this test Tensile Yield Young's Density strength strength modulus Elongation Hardness group (g/cm³) (ksi) (ksi) (GPa) (%) (HRC) A0 4.40-4.45 130-155 125-150 100-120 9-18 29-36 A1 4.35-4.39 165-175 145-165 115-150 9-18 33-39

As can be seen from the above test results, the density of the golf club head alloy according to the present invention (group A1) is lower than the density of the conventional golf club head alloy (group A0) and, thus, can be used to produce a lighter golf club head. Furthermore, the tensile strength of the golf club head alloy according to the present invention is slightly larger than the density of the conventional golf club head alloy.

(B) Cannon Shot Test of the Golf Club Head

In this test, golf club heads (group B1) produced from the golf club head alloy by the sheet blank formation step S1, the annealing step S2, the club head semi-product formation step S3, and the aging heat treatment step S4 are compared with golf club heads (group B0) produced from conventional golf club alloy (64-Ti) by the same procedures, and the results are shown in Table 2.

TABLE 2 cannon shot test of the golf club heads of each group in this test Thickness of striking plate Characteristic Cannon shots Group (mm) time (μs) (50 m/s) B0 3.0 251 1916 2.8 266 937 B1 3.0 251 4904 2.8 239 2396

As can be seen from the above test results, the golf club heads (group B1) produced from the golf club head alloy according to the present invention can withstand more cannon shots and, thus, have a better cannon shot durability. Thus, given the same cannon shot durability as the conventional golf club heads (group B0) produced from the conventional golf club alloy (64-Ti), the striking plates of the golf club heads produced from the golf club head alloy according to the present invention can be reduced in thickness to thereby reduce the weight of the golf club heads by about 3-4 g.

(C) Effect of the Aging Heat Treatment

In this test, golf club heads (group C1) produced from the golf club head alloy by the sheet blank formation step S1, the annealing step S2, the club head semi-product formation step S3, and the aging heat treatment step S4 are compared with golf club heads (group C0) produced without the aging heat treatment step S4, and the results are shown in Table 3.

TABLE 3 cannon shot test of the golf club heads of each group in this test Bending deformation after Characteristic Cannon shots 1000 cannon shots (mm) Group time (μs) (50 m/s) Bulge Roll C0 248 3721 35 55 C1 239 4904 10 20

As can be seen from the above test results, the aging heat treatment step S4 effectively increases the cannon shot durability of the golf club heads. After many times of cannon shots, the bending deformations of the striking face in the horizontal direction (bulge) and the vertical direction (roll) are significantly reduced (smaller than 30 mm).

In view of the foregoing, the golf club head alloy according to the present invention has a density of 4.35-4.39 g/cm³ due to the composition ratio thereof and, thus, can be used to produce a light golf club head, which is the effect of the present invention.

Furthermore, the method of producing a golf club head according to the present invention uses the above golf club head alloy. Under the premise of maintaining a proper cannon shot durability, the weight of the resultant golf club head is reduced. Furthermore, by performing the aging heat treatment on the club head semi-product, the cannon shot durability of the golf club head is further enhanced, and the bending deformations of the striking face in the horizontal direction (bulge) and the vertical direction (roll) are reduced, which are the effects of the present invention.

Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. 

What is claimed is:
 1. A golf club head alloy comprises by weight percent 6.5-7.5% of aluminum, 1.0-2.5% of iron, 0.05-0.2% of silicon, less than 0.15% of oxygen, less than 0.1% of carbon, less than 0.05% of nitrogen, the rest being titanium and inevitable impurities, wherein the golf club head alloy has a density of 4.35-4.39 g/cm³.
 2. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy has an aluminum equivalent of 7.5-9.2.
 3. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy includes by weight percent 6.8-7.5% of aluminum.
 4. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy includes by weight percent 1.55-1.95% of iron.
 5. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy includes by weight percent 0.11-0.15% of silicon.
 6. A method of producing a golf club head, comprising: providing a sheet blank produced from the golf club head alloy of claim 1; annealing the sheet blank at 500-800° C. for 30-90 minutes and forming a striking plate; coupling the striking plate to a club head body to form a club head semi-product; and performing aging heat treatment on the club head semi-product at 400-700° C. for 30-240 minutes.
 7. The method of producing the golf club head as claimed in claim 6, wherein the striking plate has a tensile strength higher than 170 ksi, a yield strength higher than 150 ksi, an elongation of more than 10%, and a hardness of HRC 33-39.
 8. The method of producing the golf club head as claimed in claim 6, wherein annealing the sheet blank includes annealing the sheet blank at 650-800° C. for 40-50 minutes.
 9. The method of producing the golf club head as claimed in claim 6, wherein performing aging heat treatment includes performing the aging heat treatment on the club head semi-product at 550-650° C. for 30-120 minutes. 